Serological myeloma specific markers (monoclonal immunoglobulin, serum free light chains and immunofixation from blood and urine) will be performed at weeks 6, 12, 18 and 24 and thereafter in 3 months intervals. Bone marrow biopsies will be performed when serological markers indicate complete remission or progression, a skeletal survey once a year during follow-up. During the study, disease will be assessed according to the EBMT/IBMTR/ABMTR criteria.